Accidently lost partition !!

Hi all ! I have just face a problem that I wanted to install Linux on my system, and I emptied one drive completely and deleted it using Computer Management Console. But deleting this partition caused unstable hard disk. Like one more partition got deleted on its own. The partition I deleted was PRIMARY partition and the other partition I have lost is extended partition. Now I am having free space 30 GB unallocated, 523GB free space,672GB unknown healthy partition.Originally I have 160GB(Seagate) + 40GB(Samsung) hard disk space.

Screenshot is attached:

Can somebody recognize the problem and suggest me how to recover the lost partition ?

Thanks in advance.

Last edited by Bhullarz; 26Sep2008 at 00:08..
Reason: screenshot added

If you have not overwritten any data then you can recover the data from the lost partition...There are various tools available for such kind of data recoveries. One such tool that I use is Undo Delete.UD can recover the data lost in many cases such as after Shift Delete, HD Crash and even in the case of HD Format.....So u can use this to recover the lost data...
So b4 installing the linux recover ur data first.